1/* 2 * Process/processor support for the Hexagon architecture 3 * 4 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 and 8 * only version 2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 * 02110-1301, USA. 19 */ 20 21#ifndef _ASM_PROCESSOR_H 22#define _ASM_PROCESSOR_H 23 24#ifndef __ASSEMBLY__ 25 26#include <asm/mem-layout.h> 27#include <asm/registers.h> 28#include <asm/hexagon_vm.h> 29 30/* must be a macro */ 31#define current_text_addr() ({ __label__ _l; _l: &&_l; }) 32 33/* task_struct, defined elsewhere, is the "process descriptor" */ 34struct task_struct; 35 36/* this is defined in arch/process.c */ 37extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); 38extern unsigned long thread_saved_pc(struct task_struct *tsk); 39 40extern void start_thread(struct pt_regs *, unsigned long, unsigned long); 41 42/* 43 * thread_struct is supposed to be for context switch data. 44 * Specifically, to hold the state necessary to perform switch_to... 45 */ 46struct thread_struct { 47 void *switch_sp; 48}; 49 50/* 51 * initializes thread_struct 52 * The only thing we have in there is switch_sp 53 * which doesn't really need to be initialized. 54 */ 55 56#define INIT_THREAD { \ 57} 58 59#define cpu_relax() __vmyield() 60 61/* 62 * Decides where the kernel will search for a free chunk of vm space during 63 * mmaps. 64 * See also arch_get_unmapped_area. 65 * Doesn't affect if you have MAX_FIXED in the page flags set though... 66 * 67 * Apparently the convention is that ld.so will ask for "unmapped" private 68 * memory to be allocated SOMEWHERE, but it also asks for memory explicitly 69 * via MAP_FIXED at the lower * addresses starting at VA=0x0. 70 * 71 * If the two requests collide, you get authentic segfaulting action, so 72 * you have to kick the "unmapped" base requests higher up. 73 */ 74#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE/3)) 75 76 77#define task_pt_regs(task) \ 78 ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1) 79 80#define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk))) 81#define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk))) 82 83/* Free all resources held by a thread; defined in process.c */ 84extern void release_thread(struct task_struct *dead_task); 85 86/* Get wait channel for task P. */ 87extern unsigned long get_wchan(struct task_struct *p); 88 89/* The following stuff is pretty HEXAGON specific. */ 90 91/* This is really just here for __switch_to. 92 Offsets are pulled via asm-offsets.c */ 93 94/* 95 * No real reason why VM and native switch stacks should be different. 96 * Ultimately this should merge. Note that Rev C. ABI called out only 97 * R24-27 as callee saved GPRs needing explicit attention (R29-31 being 98 * dealt with automagically by allocframe), but the current ABI has 99 * more, R16-R27. By saving more, the worst case is that we waste some 100 * cycles if building with the old compilers. 101 */ 102 103struct hexagon_switch_stack { 104 unsigned long long r1716; 105 unsigned long long r1918; 106 unsigned long long r2120; 107 unsigned long long r2322; 108 unsigned long long r2524; 109 unsigned long long r2726; 110 unsigned long fp; 111 unsigned long lr; 112}; 113 114#endif /* !__ASSEMBLY__ */ 115 116#endif 117